1. Field of the Invention
The present invention relates to a file transfer method in a converged Internet Protocol (IP) messaging system and, more particularly, to a one-to-many file transfer method that may improve file transfer performance, security, and reliability.
2. Discussion of the Background
FIG. 1 is a schematic diagram of a converged IP messaging system 10. The converged IP messaging system 10, which has been studied by the Open Mobile Alliance (OMA), a standardization organization for mobile application software, provides such services as messaging services and file transfer services. The converged IP messaging system 10 includes a transmitting terminal server 11 in communication with a transmitting terminal 20 and a receiving terminal server 12 in communication with a receiving terminal 30.
FIG. 2 is a flow chart of a file transfer method used by a traditional converged IP messaging system. For the transmitting terminal 20 to transfer a file to the receiving terminal 30, the transmitting terminal 20 first requests the transmitting terminal server 11 to establish a connection for file transfer in operation S110. The transmitting terminal server 11 verifies whether the transmitting terminal 20 can make a file transfer in operation S120.
If the transmitting terminal 20 is able to make a file transfer, the transmitting terminal server 11 inquires from the receiving terminal server 12 whether to receive a file in operation S130. The receiving terminal server 12 verifies whether the receiving terminal 30 can receive the file in operation S140. If the receiving terminal 30 is able to receive the file, the receiving terminal server 120 inquires from the receiving terminal 30 whether to receive the file in operation S150.
If the receiving terminal 30 replies to receive the file in operation S160, the receiving terminal server 12 sends the reply to receive the file to the transmitting terminal server 11 in operation S170. If the transmitting terminal server 11 sends the reply to the transmitting terminal 20 in operation S180, the transmitting terminal 20 receives the reply and transfers the file directly to the receiving terminal 30 in operation S190. Thus, according to the traditional file transfer method, the file is transferred directly from the transmitting terminal 20 to the receiving terminal 30 in the converged IP messaging system 10.
In the converged IP messaging system 10 using the traditional file transfer method, the transmitting terminal 20 is responsible for the connection for file transfer and the management of the connection. Therefore, in a one-to-many file transfer, where the transmitting terminal 20 is transmitting a file to more than one receiving terminal 30, the transmitting terminal 20 may experience a heavy resource load since it establishes a connection for file transfer to each receiving terminal 30 and transfers the same file to each receiving terminal 30.
Additionally, in the converged IP messaging system 10 using the traditional file transfer method, after the connection between the transmitting terminal 20 and the receiving terminal 30 is established, the transmitting terminal 20 transfers the file directly to the receiving terminal 30 without passing through the converged IP messaging system 10, which may result in unstable wireless sectors and limited wireless resources. Accordingly, it may create a heavy packet loss, thus lowering file transfer performance and reliability.
Furthermore, in the converged IP messaging system using the traditional file transfer method, if the transmitting terminal 20 transfers a malicious file, the receiving terminal 30 may only rely on file extension filtering as an IP-based instant messaging program.